The present invention relates to a disposable diaper.
Disposable diapers are well known, in which a pair of cuffs longitudinally extend on the inner surface of the diaper along transversely opposite sides thereof and across front and rear sections as well as a crotch section. The pair of cuffs normally tend to rise above said inner surface to prevent body fluids from leaking laterally from the diaper.
FIG. 4 in the attached drawings is a plan view showing such a known disposable diaper as partially broken away. The diaper 100 has a basic body 105 comprising a liquid-permeable topsheet 102, a liquid-impermeable backsheet 103 and a liquid-absorbent core 104 sandwiched between these two sheets 102, 103 so as to form a front section 106, a rear section 107 and a crotch section 108 interposed between these two sections 106, 107 longitudinally of the diaper 100. A pair of water-repellent or liquid-impermeable cuffs 110 extend longitudinally along transversely opposite sides of the basic body 105 across the front and rear sections 106, 107 as well as the crotch section 108 so that these cuffs 110 may bear against the wearer's crotch as the diaper 100 is worn. Additionally, the basic body 105 is provided with elastic members (first elastic members) 116 extending along transversely opposite side edges thereof and bonded in their stretched states to the inner surface of the backsheet 103 for fitness around the respective legs of the wearer. A pair of tape fasteners 113 outwardly extend from transversely opposite side edges of the rear section 107. Each of the cuffs 110 comprises a rectangular strip of sheet having a width W. The cuff 110 has an inner side edge 115 which is a free edge and to which an elastic member (second elastic member) 114 is bonded in its longitudinally stretched state, and an outer side edge 117 extending parallel to the inner side edge 115. The outer side edge 117 and longitudinally opposite ends 118 of the cuff 110 are bonded, as indicated by oblique lines 120, to the inner surface of the diaper's basic body 105. When such diaper 100 is worn, the cuff 110 is biased under the contraction of the second elastic member 114 to rise above the topsheet 102 and to form together with the topsheet 102 a pocket (not shown) opening inwardly of the diaper 100. The cuff 110 forms a barrier of the height W against excretion as the cuff 110 rises substantially in the vertical direction in the crotch section 108. Such diaper 100 is disclosed, for example, in U.S. Pat. No. 4,695,278.
When worn, the diaper may slip down and cause a gap to be formed between the diaper and the wearer's crotch, possibly leading to excretion leakage. It is possible to avoid such excretion leakage if the cuffs form sufficiently high barriers when they rise. To achieve this with the above-mentioned known diaper 100, the width W may be dimensioned to be correspondingly large. However, such dimensioning would inevitably result in the longitudinally opposite ends 118 of the cuffs 110 bonded to the inner surface of the diaper 100 along the waist line becoming so bulky such that comfort deteriorates and, in the proximity of the waist line, the relatively wide cuffs 110 disadvantageously cover the topsheet 102 even when the cuffs 110 properly stand up in the crotch section 108. Consequently, the effective area of the topsheet 102 for liquid permeation is unacceptably reduced and thus desired rapid liquid permeation becomes difficult.
A accordingly, it is a principal object of the invention to solve the above-mentioned problems by providing substantially crescent-shaped cuffs made of a elastic sheets.